What do Thomas Paine, Walt Whitman, Abraham Lincoln and Martin Luther King Jr. have in common? According to John Nichols, Washington correspondent for the Nation and a contributing writer for In These Times, these legendary Americans were more than a little bit red. “The United States is a country that has always been and should continue to be informed by socialists, socialist ideals and a socialist critique of public policies,” Nichols writes in “The ‘S’ Word,” a search for the legacy of our homegrown radicals. “Socialist ideas, now so frequently dismissed not just by the Tories of the present age but by political and media elites that diminish and deny our history, have shaped and strengthened America across the past two centuries.”

Nichols’s history isn’t merely wishful. The party of Lincoln will be surprised to learn that in 1864 the 16th president corresponded with Karl Marx through intermediaries. Fans of Wisconsin’s anti-union legislation probably aren’t familiar with Emil Seidel, who, in 1910, became the first socialist mayor of an American city: Milwaukee. And Nichols isn’t shy about his contempt for conservatives who “romanticize the disconnected libertarian living in individualist isolation” or Third Way lefties who abandon progressive values for votes. “The point here is not to say that everyone on the left needs to embrace every aspect of socialism — or even more modestly social-democratic ideals,” Nichols writes, criticizing the centrist Obama administration as forcefully as he does Glenn Beck and Sarah Palin. “Those who stand on the left . . . would do well to consider their relationship with the one word that still has the power to frighten, inform and inspire Americans.”